Performance Analysis of Small Packets Transmission for Multiple-Input Multiple-Output Non-Orthogonal Multiple Access for 5G

Abstract

The increasing demand of download data and the Internet of Things (IoT) poses challenging requirements for 5G mobile communication, such as high spectral and energy efficiency, massive connectivity and reliability. A promising technology, non-orthogonal multiple access (NOMA), is discussed, which can address some of these challenges for 5G. An advance of the Internet of Things is that some users in the system need to be served quickly for small packet transmission. However, supporting the IoT functionality in 5G networks is challenging since connecting billions of smart IoT devices with diversified quality of service (QoS) requirements is not a trivial task, given the constraint of scarce bandwidth. Non-orthogonal multiple access provides a promising solution to provide massive connectivity by efficiently using the available bandwidth resources. In this thesis, a new multiple-input multipleoutput non-orthogonal multiple access (MIMO-NOMA) scheme is designed, where one user is served with its quality of service requirement strictly met, and the other user is served opportunistically by using the NOMA concept. The novelty of this new scheme is that, it confronts the challenge that the existing MIMO-NOMA schemes rely on the assumption that the users channel conditions are different, which is a strong assumption that may not be valid in practice. In this thesis, the developed precoding and detection strategies can effectively create a significant difference between the users’ effective channel gains, and therefore, the potential of NOMA can be realized even if the users original channel conditions are similar. Throughout the thesis, analytical and numerical results are provided to demonstrate the performance of the proposed MIMO-NOMA scheme